Looking Back: Cyclamate

The second in a series re-evaluating hazards identified in the 1950s and 60s

I still think it was a banana:memorable lies and forgettable truths

Interpersonal influences on cognition can distort memory judgements. Two experiments examined the nature of these ‘social’ influences, and whether their persistence is independent of their accuracy. Experiment 1 found that a confederate’s social proximity, as well as the content and the confidence of their utterances, interactively modulate participants’ immediate conformity. Notably, errant confederate statements that ‘lied’ about encoded material had a particularly strong immediate distorting influence on memory judgements. Experiment 2 revealed that these ‘lies’ were also memorable, continuing a day later to impair memory accuracy, while accurate confederate statements failed to produce a corresponding and lasting beneficial effect on memory. These findings suggest that an individual’s ‘informational’ social influence can be selectively heightened when they express misinformation to someone who suspects no deceptive intent. The methods newly introduced here thus allow multiple social and cognitive factors impinging on memory accuracy to be manipulated and examined during realistic, precisely controlled dyadic social interactions

Analysis of Near-Surface Relative Humidity in a Wind Turbine Array Boundary Layer Using an Instrumented Unmanned Aerial System and Large-Eddy Simulation

Previous simulations have shown that wind farms have an impact on the near-surface atmospheric boundary layer (ABL) as turbulent wakes generated by the turbines enhance vertical mixing of momentum, heat and moisture. These changes alter downstream atmospheric properties. With the exception of a few observational data sets that focus on the impact to near-surface temperature within wind farms, little to no observational evidence exists with respect to vertical mixing. These few experimental studies also lack high spatial resolution due to their use of a limited number of meteorological sensors or remote sensing techniques. This study utilizes an instrumented small unmanned aerial system (sUAS) to gather high resolution in-situ field measurements from two state-of-the-art Midwest wind farms in order to differentially map downstream changes to relative humidity. These measurements are complemented by numerical experiments conducted using large eddy simulation (LES). Observations and numerical predictions are in good general agreement around a single wind turbine and show that downstream relative humidity is altered in the vertical, lateral, and downstream directions. A suite of LES is then performed to determine the effect of a turbine array on the relative humidity distribution in compounding wakes. In stable and neutral conditions, and in the presence of a positive relative humidity lapse rate, it is found that the humidity decreases below the turbine hub height and increases above the hub height. As the array is transitioned, the magnitude of change increases, differentially grows on the left-hand and right-hand side of the wake, and move slightly upward with downstream distance. In unstable conditions, the magnitude of near-surface decrease in relative humidity is a full order of magnitude smaller than that observed in a stable atmospheric regime

An IS perspective on managing change in a university

This thesis aimed firstly to explore what is happening with respect to change in a South African university, and how this change affects those involved, viewed from an IS standpoint. The focus is on determining the essence and nature of organisational change in its usual situation

An IS perspective on managing change in a university

This thesis aimed firstly to explore what is happening with respect to change in a South African university, and how this change affects those involved, viewed from an IS standpoint. The focus is on determining the essence and nature of organisational change in its usual situation

Information technology policy : first steps for the new South Africa

Bibliography: pages 183-200.The fundamental question is not whether South Africa should have a National Information Technology Policy to exploit Information Technology (IT), but more fundamentally what kind of government policies and programs for IT make sense. In today's competitive world what kind of policies and programs will be for the betterment of South Africa's economic and social structures? How can the South African government use IT to increase international competitiveness, and at the same time enhance economic and technological progress and create social improvement in the country? These and many other fundamental questions are the basis for this investigation. The starting point of this research was to compare South African IT to that in other countries; Expert opinion was obtained to identify specific issues, goals and technologies, and to propose ideas for government policies to: i) increase the country's competitiveness, ii) enhance its economic and technological progress, and iii) uplift its people. The main points emerging from this research are that the South African government needs to formulate a National IT Policy in order to direct the development of IT. Competitiveness, progress and social upliftment are inseparable and must be balanced when positioning such a policy. The policy should be directed from a high level to ensure that its recommendations are followed

Development of Versatile Strategies for Aryne Annulation: Applications in Methodology and Natural Product Total Synthesis

Since the elucidation of its structure in 1953, benzyne has been the focus of intense interest within the chemical community. Due to an unusually high degree of ring strain, benzyne displays reactivity uncharacteristic of common alkynes, including a tendency to react under mild metal-free conditions. This reactivity is exploited in the development of three novel methods for the synthesis of heterocyclic structures. The first synthetic methodology includes two orthogonal annulation reactions taking place between functionalized enamines and arynes. The substitution at the nitrogen atom of the enamine determines the path of reactivity. Carbamates undergo a formal [3 + 2] cycloaddition with arynes to give rise to indolines, while amides undergo a formal [4 + 2] cycloaddition and dehydration to form isoquinolines. The latter reaction is applied to a three-step synthesis of the antispasmotic pavine alkaloid, papaverine. This isoquinoline-forming aryne annulation reaction is further employed in a concise asymmetric total synthesis of the tetrahydroisoquinoline antitumor antibiotic, (–)-quinocarcin. In addition to this key transformation, the synthetic route features an auxiliary-mediated diastereoselective dipolar cycloaddition to set the absolute stereochemistry and a novel two-step reduction to form the tetrahydroisoquinoline. In total, this strategy has enabled the shortest total synthesis of this important alkaloid reported to date. The second methodology involves the synthesis of 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from β-ketoesters using an aryne acyl-alkylation reaction in combination with an in-situ condensation. This technology enables the preparation of highly functionalized polyaromatic ring systems in two steps from readily available carboxylic acid starting materials. As a demonstration of its utility, this method is employed in a rapid synthesis of the P,N-ligand, QUINAP. Finally, the development of a pair of three-component coupling reactions between arynes, isocyanides, and a third relay species is described. Phenyl esters and quinones lead to iminoisobenzofurans, while alkynes furnish iminoindenones. Procedures for the subsequent hydrolysis of these products are provided, thereby giving access to synthetically useful ortho-ketobenzamide and indenone compounds.</p